JPH04242926A - Temperature control method of semiconductor substrate, temperature control device of semiconductor substrate, and various kinds of vacuum devices - Google Patents

Abstract

PURPOSE:To provide a method for accurately controlling temperature which is important for improving yield of an ultra LSI. CONSTITUTION:A pressure within a cavity 16 which is provided within a tool for installing a semiconductor substrate 15 within a vacuum device is by a compressor 18, a gas is introduced from a pressurized tank 19 into the cavity 16 whose pressure is reduced, and the gas is expanded radically, thus enabling gas to be cooled only within the cavity 16, a gas with a small heat content to be warmed by heat exchange with the semiconductor substrate 15, and the warmed-up gas to be circulated outside the vacuum device.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the temperature of a semiconductor substrate, a temperature control device for a semiconductor substrate, and various vacuum devices.

0002

[Prior Art] Conventionally, a method for controlling the temperature of a semiconductor substrate in semiconductor manufacturing equipment involves controlling the temperature of a liquid such as water by heating or cooling it with a heater or chiller, and then circulating the temperature-controlled liquid with a liquid pump. Technology that controls the temperature of semiconductor substrates by controlling the temperature of the jig in which the semiconductor substrate is installed, and circulating liquefied gas such as helium or nitrogen inside the cavity in the jig in which the semiconductor substrate is installed. There are techniques to cool the semiconductor substrate by introducing it as a liquid or vaporized, and techniques to heat and control the temperature by installing a heater in the jig in which the semiconductor substrate is installed.

FIG. 2 shows an embodiment of a dry etching apparatus for a conventional method of cooling a semiconductor substrate. The device is a parallel plate type RIE (ReacTive IonEchi
ng) type etcher. The semiconductor substrate processing chamber 1 has an upper electrode 3 and a lower electrode 4 inside a vacuum container 2.
The structure is such that a semiconductor substrate 5 is placed on a lower electrode 4. The lower electrode 4 is provided with a cavity 6 for flowing circulating water therein. The temperature of the semiconductor substrate 5 is controlled by water kept at a predetermined temperature in the water tank 8 of the temperature controller 7, circulated through the cavity 6 of the lower electrode 4 via piping, and the temperature of the semiconductor substrate 5 is controlled by heat exchange. conduct. In this method, the temperature range for temperature control is limited to a narrow range of temperatures below the boiling point and above the freezing point of the liquid, and since liquids generally have a high heat capacity, the response time of temperature control to temperature fluctuations is long, and the accuracy of temperature control is low. There is a problem that it is bad.

0004

[Problems to be Solved by the Invention] Conventional temperature control using a liquid can only control the temperature within the range from the freezing point to the boiling point of the liquid itself, and the control accuracy cannot follow rapid temperature changes due to the large heat capacity of the liquid. Furthermore, since there is a distance between the liquid temperature control device and the jig for installing the semiconductor substrate, there is a problem in that the temperature of the liquid in the control device and the temperature in the control section differ. Methods using liquefied gas require a heat insulating device to keep the liquefied gas warm, and condensation inevitably occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for controlling the temperature of a semiconductor substrate, which controls the temperature over a wide range and with high precision, and does not cause dew condensation during cooling.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention employs a structure in which the temperature of a semiconductor substrate is controlled by utilizing temperature changes caused by expansion of gas.

[0007]

[Operation] With the above configuration, the present invention controls the temperature of the semiconductor substrate by expanding and cooling the gas inside the jig in which the semiconductor substrate is installed. The same temperature is sufficient, and since the gas discharged from the cavity is warmed by heat exchange with the semiconductor substrate and then discharged, it is possible to cool the semiconductor substrate to below room temperature without condensation, which allows high-precision semiconductor substrates to be heated. Temperature control becomes possible.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic sectional view of a dry etching apparatus using an embodiment of the present invention.

The device is a parallel plate type RI similar to the conventional example shown in FIG.
This is an E-type etcher, and like the conventional example, the semiconductor substrate processing chamber 11 has an upper electrode 13 and a lower electrode 14 in a vacuum container 12, and the semiconductor substrate 15 is installed on the lower electrode 14. . Next, a method of controlling the temperature near the cavity 16, which is a feature of the present invention, will be described. That is, the lower electrode 14 is provided with a cavity 16 for circulating nitrogen gas, and a heat sink 17 is provided in the cavity 16 to improve heat conduction efficiency. If the heat capacity of the jig for installing the semiconductor substrate is increased, highly accurate temperature control becomes possible. In this embodiment, nitrogen gas is used as the cooling gas, and the nitrogen gas is pressurized to 5 kg/cm2 by the compressor 18 and stored in the pressurized tank 19. It is introduced into the cavity 16 at 20 slm. The inside of the cavity 16 is maintained at 50 Pa by a compressor 18 having a pressure reducing function, and is cooled by introducing nitrogen gas into the cavity 16 while continuously expanding. The temperature of the semiconductor substrate 15 is controlled by this cooled nitrogen gas. Temperature adjustment is performed by adjusting the flow rate using the flow rate control valve 20 and adjusting the pressure using the compressor 18 having a function of reducing the pressure inside the cavity 16.

Although this embodiment describes the case where it is applied to a dry etching device, it can also be applied to other CVD devices,
It can be applied to various vacuum devices such as exposure projection equipment, ion implantation equipment, and sputtering equipment.

[0011]

[Effects of the Invention] As described above, the present invention utilizes the cooling effect of continuous gas expansion to control the temperature of a semiconductor substrate, so it is possible to control the temperature with high precision and over a wide range, which is important for controlling the performance of semiconductor processes. A method for controlling the temperature of a semiconductor substrate can be provided.

[Brief explanation of the drawing]

FIG. 1 (a) is a schematic configuration diagram of an apparatus used to carry out the method of controlling the temperature of a semiconductor substrate according to the present invention; FIG.
Enlarged view of part A in (a)

[Fig. 2] A schematic configuration diagram of an apparatus used to implement a conventional semiconductor substrate temperature control method.

[Explanation of symbols]

12 Vacuum container (vacuum device) 15 Semiconductor substrate 16 Cavity 17 Heat sink 18 Compressor 19 Pressurized tank 20 Flow control valve

Claims (13)

[Claims] 1. A temperature control method for a semiconductor device, characterized in that a semiconductor substrate is cooled by utilizing temperature changes caused by gas expansion. 2. The temperature control method for a semiconductor substrate according to claim 1, wherein a gas having a small heat capacity is used to enable highly accurate temperature control. 3. The method for controlling the temperature of a semiconductor substrate according to claim 2, wherein nitrogen gas is used as the gas. 4. Evacuating and reducing the pressure in a cavity provided inside a jig for installing a semiconductor substrate in a vacuum device, introducing gas into the reduced pressure cavity, and rapidly expanding the gas. The method is characterized in that the gas is cooled only within the cavity, the gas having a small heat capacity is warmed by heat exchange with the semiconductor substrate, and the warmed gas is circulated outside the vacuum device. Temperature control method for semiconductor substrates. 5. A claim characterized in that the flow rate of gas introduced into the cavity and the pressure within the cavity are adjusted in order to adjust the cooling efficiency of the gas within the cavity and control the temperature to a desired temperature. Item 4. The method for controlling the temperature of a semiconductor substrate according to item 4. 6. A cavity provided inside a jig for installing a semiconductor substrate, a valve for controlling a gas flow rate provided near an inlet of the cavity, and a valve for controlling a gas flow rate from the inlet of the cavity to the cavity. A semiconductor substrate comprising at least a pressurized tank for introducing gas into the tee, and a compressor for exhausting and depressurizing the inside of the cavity and pressurizing the gas in the pressurizing tank. Temperature control device. 7. The temperature control device for a semiconductor substrate according to claim 6, further comprising a heat sink provided inside the cavity. 8. The temperature control device for a semiconductor substrate according to claim 6, wherein the jig for installing the semiconductor substrate has a large heat capacity. 9. A dry etching apparatus comprising the semiconductor substrate temperature control apparatus according to claim 6, 7 or 8. 10. A CVD apparatus comprising the semiconductor substrate temperature control device according to claim 6, 7 or 8. 11. An exposure projection apparatus comprising the semiconductor substrate temperature control device according to claim 6, 7 or 8. 12. An ion implantation apparatus comprising the semiconductor substrate temperature control device according to claim 6, 7 or 8. 13. A sputtering apparatus comprising the semiconductor substrate temperature control device according to claim 6, 7 or 8.